| Day | Date | High/Low | Forecast |
| Mon | 13th | 79/64 | Partly to mostly cloudy through the evening. |
| Tue | 14th | 83/67 | Some clouds early but mostly sunny day. Mostly clear evening. |
| Wed | 15th | 87/70 | Sunny day. Mostly clear evening. |
| Thu | 16th | 86/66 | Mostly sunny day with some high clouds possible. Becoming partly cloudy late evening. |
| Fri | 17th | 82/65 | Partly to mostly cloudy through the evening. |
Synopsis
High pressure aloft covers much of the contiguous U.S. today (main center lower Minnesota and secondary center western Colorado…latter influencing southern California weather). The upper level wind flow pattern has been favorable to import “monsoon” moisture into the Southland (since the end of last week). There will be fairly minor day to day changes with the wind flow pattern (affecting the Southwest) this week (at least, so say the numerical models). So, expect southern California will remain on the warmer than normal side. The muggy factor will vary by location, but the humid (for L.A.) weather should continue for the week and probably extend into next week too.
Although it finally warmed up at UCLA last week, it didn’t reach 80 degrees as I forecast (78 the highest reading). All the models forecast rather weak on-shore flow for the next few days. So, I’m going one more time predicting 80 degree weather for the campus area. If on-shore flow ends up stronger than predicted, the expected sunnier weather tomorrow through Thursday may not be enough to warm into the 80s (applicable to other cities near the coast). A shallow marine layer, assuming it stays (some models predict that) should add to the muggy factor in the coastal plain (warmer than normal ocean aiding the cause).
The recent influx of “monsoon” moisture has helped trigger scattered showers and brief-lived thunderstorms. Occasional sprinkles fell in parts of the L.A. Basin yesterday (another “surprise” disturbance that wasn’t predicted last week). Most activity today should remain over the mountain/desert region. Less instability is predicted tomorrow and Wednesday. Areal coverage should thus be minimal for a couple of days. A slow uptick in activity (mountain/desert region) may occur later in the week, but model agreement on how much remains poor (small differences in wind flow and moisture distribution can alter a forecast greatly)
High pressure aloft is forecast to weaken slightly toward the end of the week, and “monsoon” moisture aloft may increase modestly for at least a few days. However, temperature trends should be minor in most areas (beaches stand best chance at seasonable temperatures). No major changes are foreseen next week (just modest ups and downs in temperature…staying warmer than normal most locales). The chances for “monsoon” fueled showers and isolated thunderstorms (mostly in mountains/deserts) look better in the first half of next week. There are some model forecasts showing a shunting of “monsoon” moisture out of the state toward the end of next week (general cooling trend too), but confidence in this scenario is low for now (no consistent, run to run forecasts supporting this scenario).
Next issued forecast/synopsis should be on Monday, 20 July.